The Applicants' European patent EP-B-005225(U.S. Pat. No. 4,250,841) relates to a device of this kind, in which the channels enable the wet steam to rise on either side of the superheaters in the vicinity of the inside surface of the casing, and then to descend between two groups of superheaters to arrive at the inlet to the separators in the vicinity of the plane of symmetry.
This device requires the superheaters to be divided into two separate groups leaving a oentral space through which the wet steam to descends. This increases the diameter of the device, thereby increasing its overall bulk and its cost.
Preferred embodiments of the present invention provide a device for drying and superheating steam, with the device being of smaller bulk and weight than the above-specified prior device, while still cooling of the inside wall of the casing just as effectively.